Changeset 615e83d in mainline for uspace/lib/c/generic

Timestamp:

2018-03-08T18:25:31Z (8 years ago)

Author:

Jiří Zárevúcky <zarevucky.jiri@…>

Children:

55f068c

Parents:

e0a4686

git-author:

Jiří Zárevúcky <zarevucky.jiri@…> (2018-03-08 17:43:06)

git-committer:

Jiří Zárevúcky <zarevucky.jiri@…> (2018-03-08 18:25:31)

Message:

Turn context_save/context_restore into standard setjmp/longjmp.

Location:

uspace/lib/c/generic

Files:

• context.c (modified) (2 diffs)
• setjmp.c (modified) (2 diffs)

uspace/lib/c/generic/context.c

@@ -28 +28 @@
 
 #include <context.h>
+#include <setjmp.h>
 #include <libarch/tls.h>
 #include <libarch/fibril.h>
@@ -42 +43 @@
 void context_swap(context_t *self, context_t *other)
 {
-        if (context_save(self))
-                context_restore(other);
+        if (!setjmp(self))
+                __longjmp(other, 1);
 }
 
 void context_create(context_t *context, const context_create_t *arg)
 {
-        context_save(context);
+        setjmp(context);
         context_set(context, FADDR(arg->fn), arg->stack_base,
             arg->stack_size, arg->tls);

uspace/lib/c/generic/setjmp.c

@@ -1 +1 @@
 /*
  * Copyright (c) 2013 Vojtech Horky
+ * Copyright (c) 2018 CZ.NIC, z.s.p.o.
  * All rights reserved.
  *
@@ -30 +31 @@
  * @{
  */
-/** @file Long jump implementation.
- *
- * Implementation inspired by Jiri Zarevucky's code from
- * http://bazaar.launchpad.net/~zarevucky-jiri/helenos/stdc/revision/1544/uspace/lib/posix/setjmp.h
- */
 
 #include <setjmp.h>
 #include <context.h>
 
-// TODO: setjmp/longjmp are basically a stronger version of
-// context_save/context_restore. It would be preferable to turn
-// those two into setjmp/longjmp (all it would need is preserving the
-// return value).
-
-/**
- * Restore environment previously stored by setjmp.
- *
- * This function never returns.
- *
- * @param env Variable with the environment previously stored by call
- * to setjmp.
- * @param val Value to fake when returning from setjmp (0 is transformed to 1).
- */
-void longjmp(jmp_buf env, int val) {
-        env[0].return_value = (val == 0) ? 1 : val;
-        context_restore(&env[0].context);
+/** Standard function implementation. */
+void longjmp(jmp_buf env, int val)
+{
+        /* __longjmp defined in assembly doesn't "correct" the value. */
+        __longjmp(env, val == 0 ? 1 : val);
 }